Paving compound



UNITED STATES PATENT OFFICE.

DEYVITT C. CREGIER, OF CHICAGO, ILLI NOIS.

PAVING COMPOUND.

SPECIFICATION forming part of Letters Patent No. 429,117, dated June 3, 1890.

Application filed July 16, 18891 gerial No. 317,732. (No specimens.)

To all whom it may concern.-

Be it known that I, DEWITT C. CREGIER, a citizen of the United States, residing in the city of Chicago, county of Cook, and State of Illinois, have invented certain new and use-V ful Improvements in Paving Compounds, of which the following is a specification.

This invention relates to improvements in paving compounds in which sand is usually largely employed in connection with asphalt, coal-tar, or hydraulic cement, or two or more of these substances, and the composition then spread in a plastic condition upon a natural road-bed or a bed of sand, broken stone, gravel, or other suitably-prepared foundation.

The object of this invention is the employment, wholly or partially, in this class of pavements, as a substitute for sand, of a material having none of the objectionable disintegrating features of sand when the pavement is subjected to continuous or heavy traffic, which material, as compared with the use of sand, materially promotes a uniformity in the hardness of the paving under varying temperatures, and which will resist any tendency to destruction by reason of any such variation in temperature.

To these ends my invention, broadly stated, consists in the substitution of any suitable metallic ore for sand or gravel in any of the asphalt, coal-tar, or cement paving compounds before referred to, which substitution may be made wholly or in part without a departure from the essential feature of my invention, and by metallic ores is included iron, copper, or any other natural ores which tend to produce a hard, durable, and desirable surface for pavements.

In practice I preferably employ the combination of several materials in the following approximate proportions: properly-purified and suitably prepared Trinidad or other asphalt, ten parts; distillate of coal-tar, fifteen parts; coarse sharp sand, twenty-four parts; crude iron, copper, or other metallic ore, fifty parts; sulphur, cement, lime, and salammoniac in equal proportions, one part; but it will be no departure from my invention, as before stated, to substitute metallic ores for sand in any of the well-known paving compounds containing sand in connection with either asphalt,

coal-tar, or hydraulic cement, or two or more of these substances.

The compound set forth in the foregoing tabulated statement is believed to contain the materials and about the proportion of materials of the several kinds best adapted for carrying out my invention, and which it also broadly embraces, for that it produces a compound the base of which is metallic ore combined with a suitable binding material, which, as set forth, is asphalt and coal-tar, but may be either one of these binders without the other, the proportion of cement being. so small as not to form a substantial part of said base. Preferably a metallic ore is wholly substituted for the sand; but in public-street pavements the entire substitution of metallic ore would in many cases be too expensive,

and therefore-usually only a sufficient quantity of the metallic ore is substituted for sand to secure to the paving compound when laid a degree of hardness, firmness, and durability superior to that produced by the use of sand for the purpose. By the addition of sal-ammoniac to the metallic ore it is caused to rust and become more compact in the paving, and by the addition of the sulphur, cement, and lime is established a more homoge neous com-pound.

To construct a so-called sheet-pavement composed of my improved compound, I first prepare the sub-bed of the roadway or other space to be paved and give it such shape or contour as may be desired by excavating the earth and then rolling the surface with a heavy rolling-machine. Upon this sub-bed for traffic streetsI place siX (6) inches of cubiform broken stone of a size that will pass through a ring three inches in diameter. This foundationstone is rolled with a heavy rolling-machine, so as to make it correspond with the designed contour of the roadway, after which the interstices of the stone are filled with hot distillate of coal-tar until it rises to and covers the entire surface. Upon this is laid an intermediate binding course of material two (2) inches thick, composed of small broken stone about the size of common white beans and coarse sharp sand in about equal proportions. To these is added sufficient hot distillate of coal-tar until the mass assumes the consistency of stiff mortar. This combination of materials is then spread upon the foundation course at a sufliciently high temperature to fuse the surface tar thereon, and thereby effect a union therewith, and also establish a homogeneous mass between the primary and intermediate courses. Upon this intermediate course I lay the top or wearing surface of the pavement two inches thick, composed of the asphalt, metallic ore, coarse sand, and other materials in about the proportions specified. This top or wearing surface must also be applied at a sufficiently high temperature to fuse the coal-tar of the intermediate course and be finished and compacted by suitable rollers, and thereby eifect the homogeneity of the entire three strata, and thus produce a homogeneous pavement ten (10) inches (more or less) in thickness. As soon as the materials are cooled the pavement is ready for use.

If desired, the primary foundation may be composed of stone and hydraulic cement, constituting a concrete mass; but I prefer suitably-distilled coal-tar for the purpose, used in the manner described, as a better condition of homogeneity can be secured between the courses than with the cement.

lVhen paving-blocks are made of the combination of materials herein specified for the top or wearing surface of sheet-pavement, the intermediate course is not required, and such blocks may be laid with or without any foundation, as desired.

The introduction into the materials of a wearing-surface of an asphaltic pavement, whether in sheet or in blocks of fifty per centum of metallic ore, of from forty to sixty per centum pure metal will produce a pave ment that will resist the wear and tear of trafiic to a far greater extent than any asphaltic pavement which is composed of asphalt mixed with sand or small crushed stone.

In conclusion, it is observed that Trinidad asphalt contains no sand, and that what is known as rock-asphalt, found in California, contains about twenty-four per cent. and sometimes less of crystals or sand, and therefore that in the use of rock-asphalt no sand need be added under my invention, except when necessary to embody with the asphalt additional sand in sufiicient quantity for it to include the twenty-four per cent. set forth in my formula, and this may be done without a departure from the essential feature of my invention, which, broadly stated, is the substitution of metallic ore for the larger part of the sand, usually combined with asphalt, coaltar, or cement or two or more of these substances for producing a paving compound.

Having described my invention, what I claim, and desire to secure by Letters Patent, 1s

1. The herein-described paving compound, the base of which consists of asphalt, coal-tar, metallic ore, and cement, substantially in the proportions specified.

2. The herein-described paving compound, composed of asphalt, coal-tar, metallic ore, sal-ammoniac, and cement, substantially in the proportions specified.

The herein-described paving compound, composed of asphalt, coal-tar, metallic ore, cement, and lime, substantially in the proportions specified.

DElVITT C. CREGIER.

Witnesses:

JNo. G. ELLIOTT, W. R. OMOHUNDRO. 

